This is a circa 1920 "load center" also known as a switch and fuse panel. No fuses are present in it now. Each fuse -- cylinder shaped, about 1/2" in diameter, with copper caps on each end -- would clip into a pair of the horizontal holders arranged in two columns on the left and right sides of the box. With the exception of the lowermost two circuits on the right side of the panel, each circuit also has a knife switch. The switches are arranged in pairs where the pivoting "knife" parts of each are attached to a black knob. The switch pair in the lowermost position on the left side of the panel is "open," meaning the circuits are "broken" or off. All the other switch pairs are "closed," meaning the circuits are "made" or on. In a modern "load center" circuit breakers are for the most part used in lieu of fuses. These behave something like switches, opening automatically when an individual circuit is overloaded. They have to be reset, or closed, manually once the overload condition is eliminated, but do not have to be replaced like fuses. The interesting thing about this panel is that it was probably used in a direct current (DC) application because there are "+" and "-" markings adjacent to the master fuse lugs at the top of the panel. DC applications are rare today, but were much more common before WWII. Magpie's office, until very recently, had an elevator system that ran on DC which ConEd converted to alternating current (AC) for no charge simply because the antiquated equipment was so burdensome to maintain. Who knows, this panel could be a left-over from that conversion!
2 comments:
Not fuses, but circuit breakers.
This is a circa 1920 "load center" also known as a switch and fuse panel. No fuses are present in it now. Each fuse -- cylinder shaped, about 1/2" in diameter, with copper caps on each end -- would clip into a pair of the horizontal holders arranged in two columns on the left and right sides of the box. With the exception of the lowermost two circuits on the right side of the panel, each circuit also has a knife switch. The switches are arranged in pairs where the pivoting "knife" parts of each are attached to a black knob. The switch pair in the lowermost position on the left side of the panel is "open," meaning the circuits are "broken" or off. All the other switch pairs are "closed," meaning the circuits are "made" or on. In a modern "load center" circuit breakers are for the most part used in lieu of fuses. These behave something like switches, opening automatically when an individual circuit is overloaded. They have to be reset, or closed, manually once the overload condition is eliminated, but do not have to be replaced like fuses. The interesting thing about this panel is that it was probably used in a direct current (DC) application because there are "+" and "-" markings adjacent to the master fuse lugs at the top of the panel. DC applications are rare today, but were much more common before WWII. Magpie's office, until very recently, had an elevator system that ran on DC which ConEd converted to alternating current (AC) for no charge simply because the antiquated equipment was so burdensome to maintain. Who knows, this panel could be a left-over from that conversion!
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